Automatic motor-starter.



G. T. HENDERSON C. H. MILLER. AUTOMATIC MOTOR STARTER. APPLICATION FILED JAN. 7, 1905. 921 ,398, Patented May 11, 1909.

2 SHEETS-SHEET l.

O. T. HENDERSON & C. H. MILLER.

AUTOMATIC MOTOR STARTER.

APPLICATION FILED JAN. 7, 1905.

921 ,398, Patented May 11, 1909.

2 SHEETS-SHEET 2.

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pressure in the desired manner,

CLARK 'r. HENDERSON AND CHARLES H. MILLER, or MILWAUKEE, wIsooNsIN.

AUTOMATIC MOTOR-STARTER.

Specification of Letters Patent.

Ifatented May 11, 1909.

Application filed January 7, 1905. Serial No. 240,107.

To all whom it may concern:

Be it known that we, CLARK T. HENDER- SON and CHARLES H. MILLER, citizens of the United States, residing at Milwaukee, in the county of Milwaukee and State of W'isc'onsin, have invented new and useful Improvements in Automatic Motor- Starters, of which the following is a full, clear, concise, and exact description, reference being had to the accompanying drawing, forming a part of this specification.

Our invention relates to improvements in electrically operated switches, our objectbeing to provide an automatically operated device 'which may be used to close the circuit for starting electric motors, or in any position where it is desirable to close an electric circuit by means of anelectrically operated switch. a I

A further object of our invention is to provide an automatically controlled switch which may be operated by the variations in pressure in a fluid pressure tank or reservoir.

In the drawings showing the preferred embodiment of our invention, Figure 1 is a View showing our invention in connection with a device for supplying compressed air; Fig. 2 is a diagrammatic view showing the circuit arrangement for the same; and, Fig. 3 is a diagrammatic view showing the circuit arrangement of a modification.

In the preferred embodiment of our invention, a suitable compressor 1 is provided for compressing air in a tank or reservoir 2, from which pressure may be supplied, for any suitable purpose, asfor air brakes or other suitable devices. The compressor may be connected with the motor 3, in any although I have shown in the drawings a series of gears 4, for connecting the same with the motor, and as the compressor is operated by the motor, the tank will be supplied as needed.

The operation of the motor is controlled by a pressure regulator 5, which is provided with a Bourbon tube receiving pressure from the tank 2 through the pipe 6-, and operating a switch arm 7 for controlling the electrically operated switch 8. This electrically operated switch is suitably operated to close or open the circuit to the motor.

In operation, when the pressure in the reservoir decreases to a predetennineddegree, the switch arm 7 of the pressure regu- 27 in circuit, the solenoid lator will engage a contact 9, thereby closmg a circuit for the current from the opposite side 10 of the main line through the winding 11 of the solenoid 12 of the electrically operated switch 8, through the conductor 13, switch arm'7, contact 9, thence by conductor 14 to the terminal 15, across the bridge 16 to the terminal 17, and thence by conductor 18 to the opposite side 19 of the main. The current passing through the winding 11 will energize the same, and the core thereof will be attracted, thereby operating the contact 20 to bridge the terminals 21 and 22 which will close the motor circuitand the compressor will be operated to increase the supply of fluid pressure in the tank. The motor circuit may be readily traced from the main 10 by conductor 23, through the series field winding 24, and the armature 25' of the motor, thence by conductor 26 to terminal 21, across the bridge 20, to terminal 22 and from thence to the opposite side 19 of the main.

When the solenoid switch is operated to close the motor circuit, its plunger raises the bridge 16 to break circuit between the terminals 15 and 17, thereby inserting a resistance 27 in circuit in series with the winding 11 of the solenoid 12. With the resistance winding 11 will be protected against excessive currents, and sparking will be prevented when the contact arm 7 leaves the contact 9. Upon the opening of the switch 16, the switch contact 28 will be caused to bridge the terminals 29 and 30. When the pressure in the tank 2 has reached a predetermined point, the contact.

arm 7 will .be moved into engagement with the contact 31, and the solenoid winding 11 will be short .circuited. The circuit in this instance being traced from the main 10 by conductor 32, to the terminal 30, across the bridge contact 28, to terminal by conductor 33 to contact 31, through the switch arm 7. to conductor 13, through the resistance 27, and to the terminal 17 and from thence by conductor 18 to the opposite side 19 of the main. The short circuiiing of the winding 11 will deenergize the same, causing it to drop its core, thereby opening the circuit at the terminals 21 and 22, through the motor, and cause the same to cease to operate until the pressure in the reservoir 2 again falls to such a point that the contact arm 7 engages the contact 9, to close the circuit previously mentioned.

29, and thence will not operate to close the contact 20, until the contact arm 7 engages contact 9, thereby closlng a shunt clrcult around sald resistance.

our device in which the switch-28 has been eliminated. We have not shown in thls figure the device as being connected with a motor,

or other device, as such connection is fully understood, and it is not considered necessary 'to-show the same herein. In the operation of this form the contact arm 34 is adapted to make contact with either the terminal 35 to close a shunt circuit around the resistance 61, or with the contact36 to short circuit the winding 37 of an electrically operated switch 38. In the operation of this modification, as shown diagrammatically in Fig. 3, it will be assumed that the pressure in the tank has fallen below a predetermined amount. The contact 34 therefore will move until it has engaged the terminal 35 closing a shunt circuit around the resistance 61. This circuit may be traced as follows From the main 39 to the binding post 40, by conductor41, to the binding post 42, thence by conductor 43 to cbntact-35, across the contact arm 34 by conductor 44, to the terminal 45, thence by conductor 46, through the solenoid winding 37, by conductor 47, .across the lamp switch 48, and thence by conductors 49 through the lamp resistance 50 to the binding post 51, which is connected with the opposite main 52 which may be connected 1n the motor circuit or for the urpose of this invention, the opposite side 0 the line. The resistance 61 being thus sho'rt circuited, sufficient current traverses the winding 37 to cause the same to attract its core 53 and operate the contact 54 to/bridge the terminals 55 and 56, and thereby close the motor or other circuit. As the contact 54 bridges the terminals 55 and 56, the lamp switch 48 is opened by the movement of the core 53thereagainst, inserting the lamp 57in circuit with the solenoid winding 37, this circuit being traced from the conductor 47 through the conductor 58 through the lamp 57 and thenceby conductor 59 to the lamp resistance 50, as previously described. 7 As the pressure in the reservoir increases, the contact arm 34 will gradually move away from the terminal 35 and finally make contact with the terminal 36 which will short circuit the solenold wmdmg 37, and permit its core to drop opening the motor clrcuit and causing the In Fig. 3 we have shown a modification of "resistance being maintaining said winding energized to hold has moved away from the terminal 35,w\'hen the pressure begins to increase, after the startlng of the motor, it is evident that the circuit will be broken at this point so that the circuit can no longertraverse this path, but will take a new path through the conductor 60, lamp resistance 61, conductor 62, and through the solenoid 37, as has been previously described.

Having thus described our invention what we claim as new and desire to secure by Letters Patent is:

1. In a motor controller, the combination with an electromagnetically operated main switch, of a resistance arranged in circuit with the operating winding of said switch for rendering said winding ineifective to close said swltch, and an automatically operated switch adapted, when in one position, to close a shunt-circuit around said resistance, and when in another position to cause the denergization of said' winding, said connected in a circuit for said main switch closed'when said automatically operated switch is in an intermediate position.

2. In a motor controller, the combination with an electromagnetically-operated main switch, of a resistance arranged in circuit with the operating winding of said switch for renderlng said winding ineffective to close said switch, and a fluid pressure operated switch adapted, when in one position, to close a shunt-circuit around said resistance. and when in another position to, cause the denergization of said winding, said resistance being connected in a circuit for maintaining sald winding energized to hold saidmain switch closed when said pressure operated switch is in an intermediate position.

3. In a motor controller, the combination with an electror'nagnetically operated main switch, of a resistance connected in circuit with the operating winding of said switch for rendering said winding inefiective to close said switch, and a-pressure operated switch arranged to move between stops and adapted, when incontact with oneof said stops, to close a shunt-circuit around said resistance and when in contact with the other of said stops to cause *the denergizaconnected in a circuit for maintaining sai a shunt-circuit around said operating winding to cause said main switch to open, said resistance b63111 connected 1n a circuit for J11alI1fa1111l1g Slld winding energized to hold said main switch closed. when said automatically operated switch is in an intermediate position. i .5. in a motor controller, the combination with an electromagnetically operated main switch,

of a resistance arranged in circuit with the operating winding of said switch tor rendering said winding inefi'ectlve to close said switch, and a pressure actuated switch adapted, when in one position, to close a slmnt-circuit around said resistance and when in another position to close a shuntcircuit around said operating winding to cause said main switch to 0 en, saidresistance being connected in a circuit for maintaining said winding energized to hold said main switch closed while said pressure operated switch is in an intermediate position.

6. In a motor controller, the combination with 111 electromagnetically operated-main switch, of a resistance connected in circuit with the operating winding of said switch for renderingsaid winding ineffective to] close said switch, a normally open shuntcircuit around said resistance, an automatically operated switch adapted, when in one position, to close said shunt-circuit around said resistance and when in another position to render said winding inefiective to hold said switch closed, and means operated upon the closure -of said main switch for opening said shunt-circuit around said re.- sistance, said resistance being connected in a maintaining circuit for rendering said winding eifective to hold said main switch closed. a

7. In a motor controller, thecombination with an electromagnetically operated main switch, of a resistance connected in circuit with the operating winding of said switch for rendering said winding ineffective to close said switch, a normally open shuntcircuit around said resistance, a pressure operated switch movable between stops and adapted, when in engagement with one of said stops, to close said shunt-circuit around said resistance, a switch operated upon the closure of said main switch for openingsaid shunt-circuit around'said reslstance, sa1 d resistance being connected in a maintaining circuit for said winding.

8. In a motor controller, the combination with an electromagnetically operated main switch, a resistance. arranged in circuit with the operating winding of said -switch for rendering said winding inefiective to close said switch, a normally open shunt-circuit around said resistance, a normally open shunt-circuit around said winding, an automatic switch adapted, when in one position, to close one of said shunt-circuits and @when in another position to close the other of said shunt-circuits, said resistance establishing a maintaining circuit for said winding, and a switch connected in each of said shunt-circuits and adapted to be actuated upon the closure of said main switch.

9. In a motor controller, the combination with an electromagnetically operated main switch, a resistance arranged in circuit with the operating winding of said switch for rendering said winding ineifect-ive to close said switch, a normally open shunt-circuit around said resistance, a normally open shunt-circuit around said winding, and a pressure operated switch adapted, when in one position, to close one of said shunt-circuits and when in another position to close the other of said shunt-circuits, said resistance forming a maintaining circuit for said winding, and a switch connected in each of said shunt-circuits, one of said last men- -tioned switches being arranged to be opened and the other closed when said main switch is closed.

10. The combination with a magnetically operated switch, of means for reducing the current traversin the operating magnet of said switch, a pressure which in one position renders sald. means ineffective and in another position closes a shunt circuit around said magnet, and a switch in said circuit adapted to be closed when said magnet is operated.

11. The combination with a magnetically .operated switch, of a resistance arranged the circuit of the operating magnet of sald switch, .a shunt. extending around said .resistance, a fluid pressure operated switch which in one position closes said shunt and in another position closes-a shunt circuit around said magnet, and a normally opened switch in said second mentioned shunt circuit adapted to be closed when said magnet .is operated.

12. The combination with a magnetlcally operated switch, of means for reducing the current traversing the operating magnetof said switch, a switch which in one posltlon renders saidmeans inefl'ective and in another position closes a shunt circuit around evice responsive to fluid said magnet, and a normally opened switch in said shunt circuit adapted to be closed when said magnet is operated.

13. The combination with amagnetically operated switch, of a resistance external to said switch and normally in series with the winding of the magnet for said switch ,to render said magnet inoperative, a normally open low-resistance shunt circuit around said resistance, a normally open low resist ance shunt circuit around said magnet, means for'automatically closingsaid shunt circuit around the resistance under predetermined conditions to render said magnet operative to close said switch and means connected with said switch for introducing .When operated aresistance in series withthe winding of said switch magnet.

14. The combination with a magnetically operated switch, of a resistance external to said switch and normally in series with the winding of the magnet for said switch to render said magnet inoperative, anormally open low-resistance shunt circuit around said resistance, a normally open low resistance shunt circuit around said magnet, means for automatically closing said'shunt circuit around the resistance under predetermined conditions to render said switch magnet operative to, close said switch, means connected with said switch'for introducing when operated a resistance in series with the magnet and for closing a switch in the shunt circuit around said magnet, and

means for automatically closing under predetermined conditions, the shunt circuit around said switch magnet, whereby said switch is opened.

In witness whereof, we have hereunto subscribed .our names in, the presence of twowitness'es.

CLARK T. HENDERSON. CHARLES H. MILLER. Witnesses: 1 HENRY H. CUTLER,

.I. F. HAWKINS. 

